Experiment Quality Assurance

Recording duration and trial count validation for EEG and fNIRS modalities.

Recording Duration

Modality Duration (s) Status
EEG 1145.5s ✓
fNIRS 1145.5s ✓

Valid Trials

Modality Valid Trials Expected Trials Percentage
EEG 24 24 100.0%
fNIRS 24 24 100.0%

EEG Channel Quality (Raw Data Metrics)

Channel Amplitude Range (ÂĩV) Std Dev (ÂĩV) Mean Correlation
Fp1 2.01 0.34 0.689
Fz 2.17 0.50 0.678
F3 0.84 0.09 0.136
F7 2.62 0.23 0.270
F9 1.67 0.25 -0.504
FC5 1.34 0.21 0.685
FC1 3.30 0.79 0.666
C3 2.72 0.59 0.683
T7 1.18 0.18 0.702
CP1 1.09 0.16 0.636
Pz 409.43 26.57 -0.334
P3 3.39 0.82 0.668
P7 2.68 0.59 0.684
P9 2.56 0.52 0.678
O1 1.92 0.41 0.690
Oz 3.11 0.66 0.678
O2 1.88 0.34 0.699
P10 2.78 0.63 0.684
P8 2.42 0.54 0.687
P4 1.96 0.39 0.698
CP2 2.69 0.59 0.683
T8 86.43 9.06 -0.426
C4 3.50 0.84 0.667
Cz 2.30 0.50 0.677
FC2 2.68 0.61 0.680
FC6 0.91 0.11 0.130
F10 1.30 0.17 0.661
F8 1.42 0.21 0.699
F4 2.16 0.43 0.684
Fp2 0.80 0.10 0.446

📊 SUPRA-SECTION 1: EEG ANALYSIS

Analysis of motor cortex activity during finger tapping task using 4 good EEG channels (C3, C4, F3, F4).

1.0 EEG Power Spectral Density (Preprocessed)

EEG Power Spectral Density

1.0.1 Left Hemisphere PSD by Condition

Electrodes: FC1, FC5, C3, CP1, CP5 (left motor cortex cluster)

Left Hemisphere PSD by Condition
Left Hemisphere Topoplot

1.0.2 Right Hemisphere PSD by Condition

Electrodes: FC2, FC6, C4, CP2, CP6 (right motor cortex cluster)

Right Hemisphere PSD by Condition
Right Hemisphere Topoplot

1.0.3 Time-Frequency Maps (Most Informative)

Time-Frequency Representation (TFR) showing power changes across time and frequency for motor cortex channels C3 and C4.

Expected patterns:

  • Blue patch (ERD): Power decrease in 8-30 Hz starting before movement onset (motor planning) and continuing during execution
  • Red patch (ERS): Power increase in Beta (~20 Hz) after movement ends (motor inhibition/rebound)
  • Contralateral effect: C3 shows stronger ERD for RIGHT hand, C4 shows stronger ERD for LEFT hand

Color scale: Blue = desynchronization (ERD), Red = synchronization (ERS), White = no change from baseline

Time-Frequency Maps

1.0.4 Contralateral ERD/ERS Timecourse

Classic motor cortex desynchronization: C3 desynchronizes during RIGHT hand movement (contralateral), C4 desynchronizes during LEFT hand movement (contralateral). Shows alpha (8-13 Hz) and beta (13-30 Hz) bands.

Contralateral ERD/ERS Timecourse

1.0.5 Contralateral ERD/ERS Spatial Distribution

Topographic maps showing ERD/ERS spatial distribution during task execution (2-4s after onset). Blue = desynchronization (ERD), Red = synchronization (ERS). Bottom row shows LEFT-RIGHT contrast highlighting contralateral effect.

Contralateral ERD/ERS Topoplots

Event-Related Desynchronization (ERD) Analysis

Analysis Channel: C3

Metric Value Status
Alpha ERD (8-13 Hz) -0.3% (p=0.0500) ✗
Beta ERD (13-30 Hz) -0.2% (p=0.0500) ✗
Beta Rebound (post-task) -0.0% ✗

Expected Patterns:

  • Mu ERD: -20% to -40% during task (motor cortex activation)
  • Beta ERD: -30% to -50% during movement
  • Beta rebound: +10% to +30% after task cessation

🧠 SUPRA-SECTION 2: fNIRS ANALYSIS

Analysis of hemodynamic response in motor cortex during finger tapping task.

fNIRS Quality Metrics Summary

Metric Value
Total Channels 42
Bad Channels 12
Mean SCI 0.000
Mean Saturation % 0.05%
Mean Cardiac Power 1.195
Mean CV % 1.78%

Bad Channels Details

Channel Reason
S1_D1 760 ['Low SCI (0.28 < 0.75)']
S1_D1 850 ['Low SCI (0.28 < 0.75)']
S2_D2 760 ['Low SCI (0.72 < 0.75)']
S2_D2 850 ['Low SCI (0.72 < 0.75)']
S7_D1 760 ['Low SCI (0.50 < 0.75)']
S7_D1 850 ['Low SCI (0.50 < 0.75)']
S8_D2 760 ['Low SCI (0.34 < 0.75)']
S8_D2 850 ['Low SCI (0.34 < 0.75)']
S5_D3 760 ['Low SCI (0.71 < 0.75)']
S5_D3 850 ['Low SCI (0.71 < 0.75)']
S8_D4 760 ['Low SCI (0.54 < 0.75)']
S8_D4 850 ['Low SCI (0.54 < 0.75)']

Hemodynamic Response Function (HRF) Validation

Analysis Channel: S6_D4 hbo

Metric Value Status
HbO Onset Time 0.0s ✗
Time-to-Peak 0.0s ✗
Plateau Amplitude 0.00 ξM (p=0.0500) ✗
Trial Consistency r=0.80 ✓

Expected Patterns:

  • HbO onset: 2-3s post-stimulus (neurovascular delay)
  • Time-to-peak: 4-8s for brief stimuli
  • Plateau amplitude: Significantly positive (p < 0.05)
  • Trial consistency: r > 0.5 indicates reliable response

🔗 SUPRA-SECTION 3: EEG + fNIRS (MULTIMODAL COUPLING)

Analysis of neurovascular coupling between EEG and fNIRS signals.

Neurovascular Coupling Analysis

Metric Value Status
Maximum Correlation r=nan ✗
Optimal Lag -28.0s ✓

Expected Patterns:

  • Negative lag: EEG changes precede HbO changes by 2-5s
  • Correlation strength: r > 0.4 indicates adequate coupling
  • Interpretation: Neural activity drives hemodynamic response
======================================================================
VALIDATION CRITERIA ASSESSMENT
======================================================================

EEG Analysis (Motor Cortex Activation):
----------------------------------------------------------------------
[FAIL] Alpha ERD significant: -0.3% (p=0.0500)
[FAIL] Beta ERD significant: -0.2% (p=0.0500)
[FAIL] Beta rebound observed: -0.0% post-task

EEG Summary: 0/3 criteria met

fNIRS Analysis (Hemodynamic Response):
----------------------------------------------------------------------
[FAIL] HbO onset detected: 0.0s (expected: 2-3s)
[FAIL] Time-to-peak plausible: 0.0s (expected: 4-8s)
[FAIL] Plateau amplitude significant: 0.00 ΞM (p=0.0500)
[PASS] Trial consistency acceptable: r=0.80 (threshold: >0.5)

fNIRS Summary: 1/4 criteria met

Neurovascular Coupling:
----------------------------------------------------------------------
[PASS] EEG precedes fNIRS: lag=-28.0s (negative expected)
[FAIL] Correlation strength adequate: r=nan (threshold: >0.4)

Coupling Summary: 1/2 criteria met

======================================================================
OVERALL: 2/9 criteria met (22%)
======================================================================

✗ RECOMMENDATION: Validation failed. Major issues detected.
  Significant problems with:
  - EEG signal quality or task engagement
  - fNIRS optode coupling or hemodynamic response

  Recommend troubleshooting before proceeding.

Diagnostic Suggestions:
----------------------------------------------------------------------
â€Ē Alpha ERD not significant: Check C3 electrode placement,
  verify subject engaged in task, consider longer task duration
â€Ē Beta ERD not significant: Verify movement execution,
  check for excessive muscle artifacts
â€Ē HbO onset not detected: Check optode coupling (SCI),
  verify task timing, consider motion artifacts
â€Ē Plateau amplitude not significant: Check optode placement,
  verify task difficulty sufficient to elicit response
â€Ē Weak coupling correlation: May indicate poor signal quality
  in either EEG or fNIRS, or weak task-related activation

Pipeline Configuration

Configuration parameters used for this analysis:

    {
  "eeg_enabled": true,
  "fnirs_enabled": true,
  "eeg_channels_of_interest": [
    "C3",
    "C4"
  ],
  "trials_per_condition": 12,
  "task_duration_sec": 15.0,
  "rest_duration_sec": 15.0
}